Abstract: The invention relates to the compounds of general formula: ##STR1## in which: X denotes either an oxygen atom, or two hydrogen atoms;Y denotes either a hydrogen atom, or a hydroxyl group;or Y denotes an amino group on condition that X denotes two hydrogen atoms;R denotes a hydrogen atom, or a straight- or branched-chain alkyl group having 1 to 6 carbon atoms, optionally substituted with one or more hydroxy, amino, mercapto, methylthio or carboxy groups, or aryl groups such as phenyl, pyridyl or thienyl; ##STR2## denotes a polycyclic nitrogenous structure; their enantiomers, epimers and diastereoisomers, as well as their addition salts with a pharmaceutically acceptable acid or base.

Abstract: Compounds of general formula (I): ##STR1## in which: R denotes a hydrogen atom, a halogen atom or a hydroxy, lower alkyl, lower alkyloxy, carboxyl, (lower alkyloxy)carbonyl, (lower arylalkyloxy)carbonyl, aminocarbonyl, (lower mono- or dialkyl)aminocarbonyl or (lower arylalkyl)aminocarbonyl group, an aminocarbonyl group N-substituted with a heterocyclic radical, or a thio, (lower alkyl)thio, sulfonyl or (lower alkyl)sulfonyl group,R.sub.1, R.sub.2, R.sub.3 and R.sub.4, which may be identical or different, denote a hydrogen atom, a halogen atom or a lower alkyl, lower alkenyl, lower alkyloxy or lower alkenyloxy group, optionally substituted with one or more halogen atoms,their isomers, enantiomers, diastereoisomers and also, when R denotes a carboxyl, their addition salts with a pharmaceutically acceptable base and, when R contains a basic group, their addition salts with a pharmaceutically acceptable acid.

Abstract: Compounds of general formula (I): ##STR1## in which: R.sub.1, R.sub.2, R.sub.3 and R.sub.4, which may be identical or different, denote a hydrogen atom, a halogen atom or a lower alkyl, lower alkenyl, lower alkyloxy or lower alkenyloxy group, optionally substituted with one or more halogen atoms,R.sub.5 denotes a carboxyl, (lower alkyloxy)carbonyl, (lower alkenyloxy)carbonyl or (lower alkynyloxy)-carbonyl,their isomers, stereoisomers and diastereoisomers, and also their addition salts with a pharmaceutically acceptable base.Medicinal products.

Abstract: Tetrapeptide compounds of general formula: ##STR1## in which R denotes:a hydrogen atom,a straight- or branched-chain alkyl radical containing from 1 to 4 carbon atoms,an aryl radical such as phenyl or a heterocyclic aromatic radical such as thienyl, optionally substituted with a hydroxy, amino, mercapto, methylthio or lower alkyl group,a lower aralkyl radical such as benzyl,R' denotes a hydrogen atom or a straight- or branched-chain alkyl group containing from 1 to 4 carbon atoms,X denotes an oxygen atom or an NH group,Y denotes an oxygen or sulfur atom when X denotes an NH group, or Y denotes an NH group when X denotes an oxygen atom,t denotes 0 or 1, ##STR2## denotes a nitrogen-containing polycyclic structure, their enantiomers, epimers and diastereoisomers, as well as their addition salts with a pharmaceutically acceptable acid or base.Medicinal products.

Abstract: The invention relates to N-(23-vinblastinoyl)compounds of 1-aminomethylphosphonic acid of general formula I ##STR1## in which: R.sub.1 denotes a hydrogen atom, a linear or branched alkyl radical containing from 1 to 6 carbon atoms, a linear or branched alkylene radical containing from 1 to 6 carbon atoms, an arylalkyl radical having 7 to 10 carbon atoms and capable of bearing a halogen atom as a substituent on the aromatic ring, a hydroxyl radical or an alkyl or alkoxy radical each containing from 1 to 5 carbon atoms, a 2-indolylmethyl radical, a 4-imidzolylmethyl radical or an alkoxycarbonylmethyl radical containing from 3 to 11 carbon atoms,R.sub.2 and R.sub.3, which may be identical or different, each denote a linear or branched alkyl radical containing from 1 to 4 carbon atoms,in the form of a mixture of diastereoisomers or of pure isomers, their N.sup.b' -oxides and their addition salts with a pharmaceutically acceptable inoranic or organic acid.These compounds are antitumor agents.

Abstract: The invention relates to tetrapeptide derivatives of the general formula ##STR1## in which R represents a hydrogen atom, a straight-chain or branched alkyl radical containing from 1 to 5 carbon atoms, optionally substituted by a hydroxy, amino, mercapto, methylthio, methylsulphoxide, carboxy or guanidino group, or a benzyl or indol-3-ylmethyl radical optionally substituted by a hydroxy group,R.sub.1 represents a hydrogen atom or an alkyl group containing from 1 to 4 carbon atoms, ##STR2## represents a nitrogenous polycyclic structure, the enantiomers, epimers and diastereoisomers thereof, as well as to the pharmaceutically acceptable acid or base addition salts thereof.

Abstract: New oxaazaphosphorine compounds corresponding to the formula: ##STR1## in which R is alkyl, cycloalkyl or alkoxy,phenyl, phenylalkyl, phenoxy or thiophenoxy in which the phenyl ring may be substituted by alkyl or alkoxy or by halogen.mono- or di-alkylamino optionally mono- or di-substituted by halogen, orpyrrolidinyl, piperidyl or morpholinyl or optionally substituted piperazinyl.These compounds may be used for antineoplastic therapy especially in the treatment of tumors.

Abstract: New nitrosourea compounds that can be used as medicaments and correspond to the general formula I ##STR1## in which R.sub.1 is hydrogen, C.sub.1 -C.sub.6 alkyl or phenyl,R.sub.2 is hydrogen, C.sub.1 -C.sub.6 alkyl, thienyl, or phenyl which may carry substituents,R.sub.3 is hydrogen, C.sub.1 -C.sub.6 alkyl, or benzyl which may carry substituents, orR.sub.2 and R.sub.3 together represent --(CH.sub.2).sub.m --, m being 3 or 4.Pharmaceutical compositions; therapeutic administration especially for the treatment of tumours.